The present invention relates to driving glasses that are favorable if a driver wears the driving glasses while he or she drives a vehicle.
Vehicle flow on roads intersecting lengthwise and crosswise are controlled by a traffic signal, and based on the color of a traffic signal, a driver makes a judgement on whether or not he or she must stop the vehicle. Therefore, it is necessary to clearly recognize the color of traffic signals even in the glaring twilight of the evening sun. Accordingly, in order to meet such a need, the present applicant previously proposed driving glasses that suppress the mean transmittance and, at the same time, intensify red (Japanese Unexamined Patent Publication No. 2000-75128).
However, although the driving glasses can clearly recognize the red color of traffic signals even in early morning and twilight, the glasses cannot block out ultraviolet rays reliably nor intensify green in addition to the above feature. Also, in taking other glasses into consideration, there are no glasses that can intensify red and green colors, suppress glare due to reflection waves on a sea surface, and block out thermic rays from the sun. For this reason, for example, a driver is subjected to a hindrance when driving a vehicle along seashores in the summer season.
In addition, if driving glasses that are able to intensify red and green colors, and at the same time, can vary its transmittance in response to the surrounding brightness are achieved, the driving glasses can be adapted and are very effective in a driving environment where a vehicle repeatedly passes through tunnels.
And as a matter of course, it is necessary that the driving glasses meet the standards of the ANSI (American National Standard Institute) Z80.3 as sunglasses. That is, where red is intensified by setting an absorption peak of the light transmittance in the vicinity of 570 nm through 590 nm, if the light transmittance is almost zero in the range as in the characteristics shown in FIG. 6 through FIG. 8 of, for example, the U.S. Pat. No. 6334680, safety is insufficient as driving glasses, and the glasses do not withstand the related laws and regulations in practice. Further, it is necessary that the material of driving glasses is a composition which can be chemically strengthened.
The invention was developed in view of the above-described problems, and it is therefore an object of the invention to provide driving glasses that are able to clearly recognize green along with red, under the premise of meeting the standards of ANSI Z80.3. Also, it is another object of the invention to provide driving glasses that are able to suppress glare due to reflection waves on a sea surface and block out thermic rays from the sun while the glasses can clearly recognize red and green colors under the premise of meeting the standards of ANSI Z80.3. Also, it is still another object of the invention to provide driving glasses that are able to clearly recognize red, and at the same time, securely block out ultraviolet rays under the premise of meeting the standards of ANSI Z80.3.
In order to achieve the above-described objects, the first aspect of the invention resides in driving glasses having a functional layer or an anti-reflection layer, which are composed of a metal or an organic substance, formed on the outer surface of a glass matrix. The above-described glass matrix contains neodymium oxide Nd2O3 of 1 through 12% by weight and praseodymium oxide Pr6O11of 0.5 through 8% by weight, and forms an absorption peak of light transmittance at a wavelength of 510 through 540 nm and a wavelength of 570 through 590 nm. In the present aspect, since the absorption peak of the light transmittance is formed at a wavelength of 510 through 540 nm and a wavelength of 570 through 590 nm, red and green can be clearly recognized. However, according to the composition of the aspect, no adverse effect, by which light transmittance becomes zero at the absorption peak, occurs as in the invention of the U.S. Pat. No. 6,334,680.
The content of neodymium oxide Nd2O3 is further favorably 3 through 10% by weight, and still further favorably 5 through 7% by weight. Also, the content of praseodymium oxide Pr6O11 is further favorably 1 through 7% by weight, and still further favorably 2 through 5% by weight. And, the content ratio of neodymium oxide Nd2O3 and praseodymium oxide Pr6O11 is 3:1 through 1:1 as a favorable range, is further favorably 2:1 through 1.5:1 and is optimally 1.75:1 or so. In addition, it is favorable that the total amount thereof is 5 through 15% by weight.
In the aspect, glass-forming oxides such as silicon oxide SiO2 and boron oxide B2O3, etc., and glass-modifying oxides such as barium oxide BaO, sodium oxide Na2O, potassium oxide K2O, etc., are used, and it is further preferable that a degassing agent such as stibium oxide Sb2O3 is used. In such a case, the ratio thereof in terms of weight is such that silicon oxide SiO2 is 35 through 70%, boron oxide B2O3 is 2 through 10%, barium oxide BaO is 2 through 12%, sodium oxide Na2O is 10 through 25%, and stibium oxide Sb2O3 is 0 through 1%.
An example of using potassium oxide K2O is omitted, potassium oxide K2O may be used instead of sodium oxide Na2O. Further preferably, it is satisfactory that sodium oxide Na2O and potassium oxide K2O are concurrently used. In this case, it is favorable that the total amount of sodium oxide Na2O and potassium oxide K2O is 10 through 25% by weight.
Also, it is favorable that, as other constituents, zinc oxide ZnO of 0.05 through 3% by weight, cerium oxide CeO2 of 0.1 through 2% by weight, and nickel oxide NiO of 0.05 through 3% by weight are contained.
Also, the second aspect of the invention resides in driving glasses having a functional layer or an anti-reflection layer, which are composed of a metal or an organic substance, formed on the outer surface of a glass matrix. The above-described glass matrix contains neodymium oxide Nd2O3 of 0.5 through 8% by weight and contains one or more, which is (are) selected from titanium oxide TiO2, iron oxide Fe2O3 and cerium oxide CeO2, of 1 through 25% by weight as a whole, and suppresses its light transmittance of a wavelength of 400 nm or less substantially to zero, in a glass thickness of 1.75 mm or more, and at the same time, forms an absorption peak of the light transmittance at a wavelength of 510 through 540 nm. In the present aspect, the driving glasses can securely block out ultraviolet rays, and at the same time, clearly recognize red by the absorption peak of the light transmittance of 510 through 540 nm.
In the present aspect, the thicker the glass thickness becomes, the more the light transmittance can be suppressed. However, according to the composition of the invention, no adverse effect, by which the light transmittance becomes zero at the absorption peak, is brought about.
The content ratio of neodymium oxide Nd2O3 is further favorably 1 through 8% by weight, and still further preferably 2 through 5% by weight. In the invention, it is satisfactory that the content ratio of one or more, which is (are) selected from titanium oxide TiO2, iron oxide Fe2O3 and cerium oxide CeO2 is 1 through 25% by weight as a whole. However, typically, it is better that all of titanium oxide TiO2, iron oxide Fe2O3 and cerium oxide CeO2 are contained; and the entire content ratio thereof is 10 through 20% by weight. Also, it is favorable that the content ratios of the respective constituents are 5 through 15% by weight for titanium oxide TiO2, 1 through 6% by weight for iron oxide Fe2O3 and 1 through 7% by weight for cerium oxide CeO2.
Also, in the invention, usually, glass-forming oxides such as silicon oxide SiO2 and boron oxide B2O3, etc., and glass-modifying oxides such as barium oxide BaO, sodium oxide Na2O, potassium oxide K2O, etc., are used. It is further favorable that a degassing agent such as stibium oxide Sb2O3, etc., is used. In addition, in such a case, the ratio thereof in terms of weight is such that silicon oxide SiO2 is 35 through 70%, boron oxide B2O3 is 2 through 10%, barium oxide BaO is 2 through 12%, sodium oxide Na2O is 10 through 25%, and stibium oxide Sb2O3 is 0 through 1%. Further, it is favorable that the glass matrix contains, as other constituents, copper oxide CuO of 0.01 through 0.12% by weight, and manganese dioxide MnO2 of 0.1 through 1% by weight.
An example of using potassium oxide K2O is omitted. However, potassium oxide K2O may be used instead of sodium oxide Na2O. Further preferably, it is satisfactory that sodium oxide Na2O and potassium oxide K2O are concurrently used. In this case, it is favorable that the total amount of sodium oxide Na2O and potassium oxide K2O is 10 through 25% by weight.
In both the above-described first and second aspects, not only a common anti-reflection layer but also a thermic ray reflection layer for reflecting thermic rays are preferably selected. Herein, a metal layer and an organic substance layer may be considered as the thermic ray layer. Preferably, an aluminum-deposited layer is illustrated. An evaporation layer of ITO (indium tin oxide) may be acceptable. Also, in both the first and second aspects, preferably, an anti-reflection layer is formed on the inner surface of the glass matrix. In this case, eyeball reflection onto the inner surface of glass can be prevented.
The third aspect of the invention resides in driving glasses having a polarizing film provided on the inner surface or the outer surface of a glass matrix. The above-described glass matrix contains neodymium oxide Nd2O3 of 1 through 12% by weight and praseodymium oxide Pr6O11 of 0.5 through 8% by weight, and forms an absorption peak of light transmittance at a wavelength of 510 through 540 nm and a wavelength of 570 through 590 nm. The fourth aspect of the invention resides in driving glasses having a polarizing film provided on the inner surface or the outer surface of a glass matrix. The glass matrix contains neodymium oxide Nd2O3 of 0.5 through 8% by weight and contains one or more, which is (are) selected from titanium oxide TiO2, iron oxide Fe2O3 and cerium oxide CeO2, of 1 through 25% by weight as a whole, and suppresses its light transmittance of a wavelength of 400 nm or less substantially to zero, in a glass thickness of 2 mm, and at the same time, forms an absorption peak of the light transmittance at a wavelength of 510 through 540 nm.
The third and fourth aspects of the invention are featured in providing a polarizing film. However, herein, the polarizing film means that it permits an incident light beam having only a direction constituent coincident with a specified polarization angle to pass through with respect to incident light beams having an inclination constituent of 360xc2x0. Such a structure of placing a polarizing film between a glass matrix according to the invention and UV-cut glass may be illustrated as a preferable example. Since the third and fourth aspects of the invention have a polarizing film, it is possible to suppress glaring reflection light on a water surface or a snow and ice surface, wherein it is possible to securely prevent eyeball fatigue reliably.
Also, in the third aspect of the invention, preferably, photo chromic glass, in which the light transmittance automatically varies corresponding to irradiation of ultrasonic rays, is provided continuously from the above-described polarizing film. This feature is identical to that of the fourth aspect of the invention. However, also, in the case of the fourth aspect, it is favorable that a photo chromic glass, in which the amount of light transmission automatically changes in response to irradiation of light at the short-wavelength side of a visible range, is provided continuously from the above-described polarizing film.
The photo chromic glass is made into a dark color when it is exposed to ultraviolet rays and light at the short wavelength side of a visible range and is restored to its original state when the irradiated ray is eliminated. The photo chromic glass originates in that described in, for example, U.S. Pat. No. 3,208,860. Such photo chromic glass is typically produced by developing crystallite of silver halide, which is selected from a group of AgCl, AgBr, and AgI. According to U.S. Pat. No. 3,208,860, favorable base glass is oriented in a composition of R2Oxe2x80x94Al2O3xe2x80x94B2O3xe2x80x94SiO2.
In any case, where photo chromic glass is provided continuously from the above-described polarizing film, there are advantages in clear recognition of red and green and in changes in the light transmittance of driving glasses in response to surrounding brightness. Although, with the present embodiment, it is necessary to make the glass matrix thin and to increase the mean transmittance, it is favorable in view of driving glasses being made equivalently thin. In addition, in connection with the embodiment in which photo chromic glass is provided, the third embodiment is further preferable than the fourth embodiment in view of setting the light transmittance higher.
Other and further objects, features and advantages of the invention will appear more fully from the following description. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.